1. Field of the Invention
The present invention relates to a socket connector, and more particularly, to an optoelectronic socket connector is powered to transmit optical and electrical signals.
2. Description of the Prior Art
A conventional electrical connector for electrically connecting an IC package to a printed circuit board comprises an insulative housing and a plurality of contacts received therein to transmit signal and electrical current. The insulative housing comprises a bottom wall and sidewalls extending upwardly from the bottom wall. The bottom wall comprises a top surface and a bottom surface opposite to the top surface. The contacts are made of metal and each comprises a body portion, a contact portion extending beyond the top surface and a tail extending beyond the bottom surface. The body portion is positioned in the bottom wall to secure the contact in the insulative housing. The contact portion is used to contact with the pad of the IC package and the tail is used to contact with the pad of the printed circuit board. Thus, a reliable electrical connection is established between the IC package and the printed circuit board to transmit signal and electrical current.
The growing trend in the IC package field is toward more functions per chip and miniaturization. Accordingly, trend of electrical connector is toward miniaturization and more number of contacts. However, heat produced by the IC package becomes more and more. At The same time, the pitch between the contacts becomes smaller and smaller, thus the electromagnetic interference becomes more and more severe. Another problem is that the IC package presses the contact portion of the contact so as to establish engagement therebetween, if the contact portions are not located at a same height, some of the contacts will not touch the IC package. The electrical connector will not function normally.
U.S. Pat. No. 4,695,120 issued to Holder on Sep. 22, 1987 discloses an optical-coupled IC and a socket for the optical-coupled IC. As shown in FIG. 3, body 60 of the socket provides mechanical support and restraint for the IC 61 and provides means for mounting the assembly to a base plate or chassis 62. As shown, bosses 63 and 64 penetrate the chassis to provide access for the optic fibers 65 and 66. Transmission of the optic signal/data 67/68 to and from the IC 61 and the end of the optic fibers is facilitated by refractive-index matching systems 70 and 71 such as a transparent putty-like material. This material serves to decrease the signal loss and reflections in the optic path. The socket will have some restraining device for the optic fiber such as a friction ridge or spur on its inner diameter, or a clamping system possibly using a thermo-shrink or shape-memory material (not shown). However, structure of assembly of the socket and the optical-coupled IC 61 may be too complicated. Moreover, there is no individual electrical contact in the socket for transmitting electrical powering; thus electrical connection between the optical-coupled IC 61 and the socket may be inadequate and unsteady.
Therefore, it is needed to find a new socket assembly to overcome the problems mentioned above.